Information processing has progressed. Information processing includes computer aided techniques. As an example, information processing includes “text mining.” Typical text mining tasks include text categorization, text clustering, concept/entity extraction, production of granular taxonomies, sentiment analysis, document summarization, and entity relation modeling (i.e., learning relations between named entities). Classification techniques are also included in text mining. As an example, classification techniques are often general and have many diverse applications. Such classification techniques may be applied to text processing, document processing, computer vision, medical and biological sciences, among others. A goal of text classification is to assign an electronic document to one or more categories based on its contents.